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The perceived interior noise has been one of the major driving factors in the design of automotive interior assemblies. Buzz, Squeak and Rattle (BSR) issues are one of the major contributors toward the perceived quality in a vehicle. Traditionally BSR issues have been identified and rectified through extensive hardware testing. In order to reduce the product development cycle and minimize the number of costly hardware builds, however, one must rely on engineering analysis and simulation upfront in the design cycle. In this paper, an analytical and experimental study to identify potential BSR locations in a cockpit assembly is presented. The analytical investigation utilizes a novel and practical methodology, implemented in the software tool Nhance.BSR, for identification and ranking of potential BSR issues. The emphasis here is to evaluate the software for the BSR predictions and the identification of modeling issues, rather than to evaluate the cockpit design itself for BSR issues.

This paper reviews the state of the art on analytical design of cockpit modules in two most crucial performance categories: safety and comfort. On safety, applications of finite element analysis (FEA) for achieving robust designs that meet FMVSS 201, 208 and 214 requirements and score top frontal and side NCAP star-ratings are presented. On comfort, focus is placed on Noise, Vibration and Harshness (NVH) performance. Cutting-edge analytical tools for Buzz, Squeak and Rattle (BSR) avoidance and passenger compartment noise reduction are demonstrated. Most of the analytical results shown in this paper are based on the development work of a real-life application program. Correlations between the analytical results and physical test results are included. Examples of Computational Fluid Dynamics (CFD) analysis for climate control are also included. At the end, the road map toward 100 percent virtual prototyping and validation is presented.

A computational study of flow developments over airfoils with backward-facing steps is conducted to explore the possibility of enhancing aerodynamic performance of the airfoils by vortex generation. The study focuses on the effects of the separated flow and subsequent vortex formation generated by the step on pressure distributions around two airfoil profiles. Step location and size are varied to determine their effect on lift, drag, and L/D ratio. A discussion of the effects and trends of the various step configurations on airfoil performance is presented along with the results that may serve as a reference for employing a control criteria to optimize airfoil geometries during flight.

The flow over a NACA 0015 airfoil with a trailing edge jet (jet flap) is investigated using computational and experimental capabilities to determine the influence of the jet on vortex developments over the airfoil. The computational modeling of steady flow at a Reynolds number of 43,000 at fifteen and twenty degrees indicates that as the jet mass flow rate is increased, the trailing edge jet suppresses vortex development, and in some cases, reattaches the flow. Experimental visualization shows the suppression of vortex structures in both steady and accelerating flow. The trailing edge jet may thus be a possibility for vortex control.